public void ByteArrayToDottedDecimalStringTest() { var testArray = new byte[] { 0xb8, 0x27, 0xeb, 0x97, 0xb6, 0x39 }; var result = testArray.ToDottedDecimalString(); Assert.AreEqual("184.39.235.151.182.57", result, "Dotted Decimal representation not as expected"); Assert.Throws <ArgumentNullException>(() => { ByteExtensions.ToDottedDecimalString(null); }, "Not seen ArgumentNullException even though null has been passed for input"); }